1. Field Of The Invention
The invention relates to a quick release clamping device, more particularly to a quick release clamping device having provisions to prevent the untimely release thereof.
2. Description Of The Related Art
Presently, there are two methods used to mount the hub of a bicycle wheel of a bicycle fork. In the first method, a bolt extends through the hub of the bicycle wheel and a pair of nuts engage the two ends of the bolt, tightly clamping the hub between the prongs of the bicycle fork. The engaging and disengaging steps of the first method make the replacement of flat tires during competition both troublesome and time consuming.
To make it easier and quicker to mount the hub on the bicycle fork, a quick release clamping device is used. Referring to FIG. 1, a conventional quick release clamping device 1 is shown to comprise a hollow clamping cap 2 and a bolt member 3 having an enlarged head portion 3a to be disposed inside the clamping cap 2. The head portion 3a has a through bore 3b to be aligned with diametrically opposite through holes 2a on the clamping cap 2. A nut 4 is provided to engage a threaded end of the bolt member 3. A lever member 5 has an elongated handle portion 5a and a shaft portion 5b angled from and connected to the handle portion 5a. Each end of the shaft portion 5b is to be journaled in one of the through holes 2a. The shaft portion 5b has an eccentric portion 5b1 to be disposed in the through bore 3b of the bolt member 3. A locking ring 6 is provided on one of the ends of the shaft portion 5b to prevent axial sliding of the eccentric portion 5b1 inside the through bore 3b. The handle portion 5a is operated to axially move the bolt member 3 between a slack position, in which the eccentric portion 5b1 is not in contact with the head portion 3a, and a tightened position, in which the eccentric portion 5b1 pushes the head portion 3a further into the clamping cap 2, pulling the nut member 4 toward the clamping cap 2. Loosening and tightening of the clamping device 1 can thus be easily and quickly achieved by simply operating the lever member 5.
A main disadvantage of the clamping device 1 is that when the bicycle is in use, the lever member 5 is relatively unstable in the tightened position. Thus, the lever member 5 may accidentally move from the tightened position to the slack position, which might cause the untimely release of the hub from the bicycle fork, thereby causing injury to the rider.